The present invention relates to an apparatus for continuously removing particulate and volatile contaminants from engine lubricating oil and, in particular to such an apparatus wherein the oil flows over an evaporation surface such that heat drives volatile contaminants therefrom and wherein the heat is substantially provided by the oil itself. In addition the apparatus is especially suitable for use on machinery or boats wherein the apparatus is not fixed in a constant position but rather continuously tilts or rocks back and forth from a vertical orientation.
The present invention is related to our copending allowed application entitled MANIFOLDING SYSTEM FOR OIL REFINERS, Ser. No. 167,778, wherein is disclosed a manifolding and ganging apparatus which allows multiple standard sized refiners according to the present invention to be effectively used as a single unit.
It has long been recognized that lubricating oil contamination in engines is a major cause of wear and damage to such engines. Therefore, numerous conventional devices under the name of refiners, purifiers, rectifiers, or the like have been developed to remove such contamination from the oil. These devices often include filter media to remove particulate matter such as sludge, metal pieces, carbon or the like and a dispersion or evaporation surface over which the oil is passed in a relatively thin layer which surface is heated so that volatile impurities such as water, fuel fractions, or the like are driven into a surrounding chamber which in turn is vented to exhaust the volatiles to the atmosphere.
Preferably, oil refiners should filter out particles which are about 1 to 3 microns in size or larger, absorb liquid contaminants in the filter media, somewhat neutralize acidic oil in the filter media, and provide for the evaporation of volatile contaminants from the oil in a consistent and uniform manner.
In order to distribute the oil in a relatively thin layer so as to improve evaporation of volatiles therefrom, the evaporation surface of many conventional refiners is frustoconical in shape with spaced horizontal tiers or steps therealong. Such tiered surfaces provide satisfactory even layering of the oil thereon for maximization of evaporation of volatile contaminants as long as the associated refiners is fixed in position and the tiers are always horizontal. However, for many engines which are in boats or various mobile machinery and which are frequently tilted or tend to rock back and forth, the tiers do not remain in a horizontal position and hence the oil tends to collect unevenly on the tiers such that too thick a layer of oil is formed on one side thereof and too thin a layer is formed on the opposite side; if at all. The present invention has resolved the problems of providing a uniform layer by making the evaporation surface relatively insensitive to tilting or rocking of the refiner. In particular the evaporation surface of the present invention is dome shaped with the oil being placed thereon near the top thereof. In addition ribs are provided which divide the evaporation surface into sections and restrict flow of oil between adjacent sections.
It has also been found that when the oil is placed at atmospheric pressure on the evaporation surface with air circulating thereabout, the volatile contaminants will evaporate without need for external heat from such sources as an electrical resistance coil, such as are commonly used in the conventional art, if the heat of the oil itself is indirectly utilized to heat an evaporation chamber above the evaporation surface. Heating the chamber urges volatiles into the air contained in the chamber and tends to prevent condensation of the volatiles on the walls of the chamber.
In addition, it is desirous to have a refiner wherein all oil entering the refiner flows through a maximum amount of filter media and that all of the oil is subjected to passage over the evaporation surface such that a maximum amount of contaminants is removed from essentially all the oil passing through the refiner.
It is also desirous that the refiner be relatively easy to maintain and in particular that the filter media be subject to quick and easy replacement.